High-tension apparatus



Ap 3,1945. K. BISCHOFF HIGH TENSION APPARATUS Filed May 24, 1941 I5 Sheets-Sheet 1 Auer fi/SC'HOFF A 3, 1945. K. BISCHOFF HIGH TENSION APPARATUS Filed May.24, 1941 3 Sheets-Sheet 2 pom/r h I we?" Ap 3, 1945. .K. BISCHOFF HIGH TENSION APPARATUS Filed May 24, 1941 3 Sheets-Sheet 3 A/Z/E 7- 15/50/7 01 Melt/1'07:

By J

mrne y.

Patented Apr. 3, 1945 HIGH-TENSION APPARATUS Kurt Bischoff, Erlangen, Germany; vested in the Alien Property Custodian Application May 24, 1941, Serial No. 395,021

In Germany An Claims.

This invention relates to high tension apparatus, and is particularly concerned with arrangements or apparatus wherein an electrical discharge tube or a Roentgen tube is provided in a common housing or container together with a high tension generator. I

The insulation of the windings and apparatus parts which are in such apparatus subjected to the high tension against ground causes considerable difliculties. The weight of such structures should be kept as small as possible, and this requirement increases the insulating diiliculties very considerably.

In order to avoid these and other difliculties, a suggestion was made which, theoretically, appears to be correct, the realization of which is, however, extraordinarily difilcult, particularly in the case of apparatus for very high tensions (for example, tensions exceeding approximately 200,000 volts). This known suggestion is concerned with an apparatus including an electrical discharge tube built together with a high tension generator and having only a single high tension coil. The insulating layers arranged between the individual winding layers of this coil extend beyond the edge so that, upon cutting into the over lapping edges at uniform intervals, insulating flags or flaps are produced in radially extending layers, which are then lapped or folded over, for example, toward the middle of the outer side of the coil. The folding-over of these insulating flaps avoids flash-overs at the sidewalls of the coil. Built into the insulation at one point of the circumference of the coil is an electrical discharge tube which is subdivided into individual stages. In addition, a plurality of metallic potential control surfaces may be embedded in the folded insulating layers for the purpose of controlling the potential. These surfaces also control the potential along the discharge tube.

It should be assumed, from the point of view of insulating technique, that this'suggestion would lead to a satisfactory solution of the insulating problem in the building of such apparatus. The production of structures according to this suggestion is, however, made unusually difficult and complicated in view of the fact that the high tension winding consists of a single coil, and that unequally wide insulating layers must be built into the structure during the winding of the coil. Particular difiiculties are caused by the requirement that the metallic potential control surfaces must not act in the manner of shunt windings for the high tension transformer and that they must be approximated everywhere to the shape of til 27, 1940 the insulating body. It must also be considered that the structure of such a single coil high tension winding must not exceed a predetermined width in order to avoid an unfavorably high layer potential. The coil for very high tensions (about 1 million volts) must, therefore, be highly wound in order to accommodate the required number of turns, and this leads to an unfavorable condition regarding the straying which in turn affects the efliciency of the generator.

In accordance with the present invention, the

building of such high tension apparatus is made easier, simpler, more economical and also more eflicient by producing the high tension in a coil having a plurality of'winding or coil sections assembled or bandaged together in such a manner that the insulation comprises a plurality of bandages, one for each coil section, wherein each continuous bandage includes its own coil section and in addition thereto all winding or coil sections which are on a higher potential against ground. Each suchbandage extends up to 2. corresponding point of the tube housing or to a high tension conduit. These bandages are successively attached and are each provided throughout with a conducting layer for the purpose of furnishing complete potential control, thereby obtaining at every point approximately the same electrical load of the insulating material, and this conductive layer is connected with the lowest potential of the high tension generator which is included in the corresponding individual bandage. The insulation of the individual winding or coil sections, that is to say, the individual windings against ground, is at all points continuous and by the introduction of the metallic layers extending over the entire surface of the individual bandages and being connected with the windings the insulation is permeated over its entire extent up to the high tension terminals by conductive equipotential surfaces, the potential of which is controlled directly by the high tension generator. The electrical load of the insulating material can in this manner be accurately predetermined at all points. A minimum of insulating material will thus suiiice, and material as well as space is saved Without producing any undue stress that would go beyond the electrical value the material can stand.

The potential distribution within the insulation would be entirely different with identical arrangement and thickness of the bandages but with the potential control surfaces omitted. The field strength would increase very considerably from the outside to the inside according to the curvature of the surface elements which are to be insulated against ground. In the diiferent parts of the high tension generator, as well as its connecting lines leading to a heating transformer and a tube housing that may be provided, we

.must consider diiferent radii of the curves.

Therefore, the equipotential surfaces within the insulating bandages do not everywhere conform to the individual paper layers,

The production of the new divided coil high tension generator is considerably simpler than that of the previously mentioned single-coil apparatus. The coil or winding sections which are whereby, in order to avoid short circuit windings,

a strip-like surfac piece is held free at the circumference of the coil, and this piece is provided with a thin intermediate insulating layer and is also covered with a metallic layer which i conductively connected with the first noted metallic layer. (Figs. 1A, 1B, 1C and 1D.)

Theinvention is schematically shown in the accompanying drawings, wherein Figs. 1 and 2 schematically illustrate two embodiments, partially in section and partially in plan view, of structures for producing very high tensions, and particularly of high tension generators built together with discharge tubes or Roentgen tubes.

Fig. 1A is an enlarged sectional detail view of the lower left-hand portion of Fig. 1.

Fig. 1B is a detail view of a bandage made from a metallized paper strip. I

Fig. 1C is a detail View of a bandage made by spraying an insulating layer with a suitable metal.

- Fig. 1D is a detail View of a bandage made from a metal foil and an insulating layer.

In the embodiment shown in Fig. 1, the high tension generator comprises two transformers having iron cores 3 and It assembled together with the two-stage Roentgen tube I in a common container 2. Each of these transformers has two primary windings 5 separated from each other and two secondary windings 6. The secondary windings again may consist of a plurality of individually bandaged winding or coil sections. As shown in Fig. l, the four secondarywindings 6, are bandaged together in such a manner that each successive continuous bandage 7 includes all successive individual windings 6 which are on a higher potential than the winding from which the corresponding bandage started.- The connecting liness extending between the windings within such bandage are also included therein.'

The individual bandages are therefore progressively boxed one within the other. The outermost bandage thus extends over or includes all secondary winding sections as" well as the connecting lines therefor, and also the tube I as well as the secondary winding of the heating transformer It. This bandage is connected to ground as shown. The second bandage from the outside includes allwinding sections which are on a higher potential as compared with the first winding section as well as the connections therefor and LII also the tube and the secondary of the heating transformer, and carries, for example 125 kv. The third bandage includes the next two winding sections together with their connections and also part of the tube and the secondary of th heating transformer and carries, for example, 250 kv. The fourth or innermost bandage includes merely the winding section shown at the lower left hand side of the drawings, the connections therefor, and also the cathode end of the tube and the secondary of the heating transformer. The bandages are thus boxed within one another, the outermost bandage including all other bandages and each successive bandage boxing or including only the bandage of the sections carryirig a higher potential. The individual coil or winding sections are therefore successively surrounded by insulating layers provided with conductive layers which are superposed in accordance with the individual potential prevailing in the apparatus. The conducting layers for each of these bandages l are shown at 9. They are connected at the corresponding points with the lowest potential of the parts of the high tension transformer which are embedded in the individual bandages. In the case of a total tension of the generator, which is grounded at one side, of, for example, 500 kv., the individual control surfaces 8 therefore receive the potentials 125, 250 and 375 kv. as discussed.

In accordance with another feature of the invention, the heating transformer 18 provided for the heating of the Roentgen tube I can be covered throughout in the same manner with the conductive control surfaces 9.

The Roentgen tube I is built into th progressively boxed or staggered bandage of the high tension line I I in such a manner that its cathode side I2 is in connection with the high tension line. The insulating bandages I and the control surfaces 9 terminate, as viewed from the cathode side of the Roentgen tube, from the inside to the outside in a staggered manner, and the control surfaces 9 thus serve for controlling the potential at the Roentgen tube.

In case the high tension should be conducted not to a Roentgen tube, which is provided with the generator in a common container, but, for example, to an apparatus outsid of the c0ntainer, the insulating bandages I and the control surfaces 9 may end or terminate in corresponding manner in a high tension conduit.

Another example of the invention is shown in Fig. 2; The high tension is produced in a coil which is subdivided into several winding sections it. We have again shown ths second embodiment for the sake of simplicity in connection with a high tension generator which is grounded on one side. The arrangement of the bandages I and the control surfaces 9 is here very similar to that shown in the first example. By the use of a single coil consisting of four winding section I3, which is arranged together with the primary winding I4, upon the iron core I5, the building of the entire structure is considerably simplified and made more accessible, and weight as well as space can be saved as compared with the embodiment dis cussed in connection with the first example.

As previously stated, the metallic potential control surfaces may be produced in different ways. In Fig. 1B, the bandage comprises an insulating paper layer 'Ib upon which a layer of metal 9b is secured; in Fig. 1C, the insulating layer 7c is sprayed with a metallic material and, in Fig. 1D, the insulating layer Id is covered by a metal foil M. In order 'to'prevent short circuit windings, the metallic layer for each bandage is discontinued at point A near the peripheries of the respective coils. The upper left-hand portion of Fig. 1A shows the detail structure at the point where the metallic layer is discontinued. It is here seen that a strip-like surface piece of insulating material 20 is placed over the discontinued area of the underlying bandage. This strip has a metal covering 2|, one end of which is secured to the metallic layer 9 of said underlying bandage. By discontinuing the metallic surface of each bandage in the manner shown at points A, the successive metallic layers are disconnected and thus prevents short-circuiting through the coil windings. The strip 20 and metal layer 2| serve to cover the discontinued or blank area with a metal, but at the same time prevents a connection between the conductive layers of adjacent bandages.

Changes may be made within the scope and spirit of the appended claims which define what is considered new and desired to have protected by Letters Patent of the United States.

What is claimed is defined as follows:

1. In combination, a, plurality of transformers, each transformer comprising a coil, two primary windings and a secondary winding coacting with each primary winding, a Roentgen tube, a heating transformer, insulating means comprising an insulating layer for each secondary winding of said transformers, each said insulating layers including in addition to its own secondary winding all other secondary windings carrying a higher potential and also all interconnections therebetween as well as the secondary winding of said heating transformer, and each said insulating layer eX- tending over part of said Roentgen tube, a conductive layer for each insulating layer and also extending over said tube in accordance with the potential distribution thereof, and means for connecting each conductive layer with the lowest potential carried by any secondary windin included in the insulating layer of which the corresponding conductiv layer forms a part.

2. In combination, a coil, a primary winding. a plurality of secondary windings disposed on said primary winding and forming therewith and with said core a high tension transformer, a Roentgen tube, a heating transformer, a bandage for said transformers and said tube comprising an insulating layer for each secondary winding, each said insulating layer including in addition to its own winding all other secondary windings carrying higher potential and also all interconnections therebetween as well as the secondary winding of said heating transformer and each said insulatin layer extending over partoi' said Roentgen tube, a conductive layer for each insulating layer and also extending over said tube in accordance with the potential distribution thereof, and means for connecting each conductive layer with the lowest potential carried by any secondary winding of sa d high tension transformer included in the insulating layer of which the corresponding conductive layer forms a part.

3. Roentgen apparatus having a Roentgen tube and a plurality of separate .co-il sections forming part of the transformer means for generating high voltage for said tube, a common insulation for said coil sections and for the interconnections there-- between, said insulation comprising a separate insulating layer for each coil section, each said in-- sulating layer extending over and covering ail remaining coil sections carrying a higher potential comm on insulating than its own coil section, a layer of conductive material carried by each insulating layer each of said conductive layers also extending over part of said Roentgen tube in accordance with the potential distribution thereof, and each of said layers of conductive material bein connected with the lowest potential carried by any coil section which is included in the insulatin layer to which it is attached.

4. The structure and combination defined in claim 3, wherein a heating transformer is provided, said heating transformer having a secondary winding which is covered by all of said insulating layers and the conductive layers carried thereby.

5. High tension apparatus comprising a Roentgen tube, a plurality of coil sections carrying in operation successively higher potential and forming part of a high tension generator for said tube, a common housing for said tube and said generator, an insulating layer for each coil section, each of said insulating layers except the layers for the last section, including all coil sections and interconnections between all coil sections which carry higher potential than its own coil section, a layer of conductive material for each of said insulating layers, each of said insulating and conductive layers being disposed in staggered relation around said tube in accordance with the potential distribution thereof so as to obtain a potential control for said tube, and means for connecting each conductive layer with the lowest potential carried by any coil section included in its corresponding insulating layer so as to obtain substantially perfect potential control and a substantially equal and uniform electric loading of said insulating layers throughout their entire extent.

6. Thestructure and combination defined in claim 5, together with a heating transformer wherein said insulating layers and the conductive layers thereof include said heating transformer.

7. A device for producing very high voltages comprising a plurality of serially related individual coil sections carrying successively higher potential, an insulating bandage for each of said coil sections and for the interconnections therebetween, said bandages being disposed in accordance with the serial relationship of said coil sections so that each successive bandage, except the bandage for the last coil, includes all the coil sections and all interconnections between the coil sections which carry successively higher potential, and a discharge tube for receiving said high voltage, wherein each of said bandages extends over part of said tube in accordance with the potential distribution thereof.

8. A device for producing very high voltages comprising a plurality of serially related individual coil sections carrying successively higher potential, an insulating bandage for each of said coil sections and for the interconnections therebetween, said bandages being disposed in accordance with the serial relationship of said coil sections so that each successive bandage, except the bandage for the last coil, includes all the coil sections and all interconnections between the coil sections which carry successively higher potential, a discharge tube for receiving said high voltage, and a conductive layer for each of said bandages which is coextensive therewith and is connected with a point of lowest potential carried by any said section included in the corresponding bandage, said bandages and the conductive layers thereof extending in staggered relation over said tube in accordance with the potential distribution thereof.

9. A device for producing very high voltages comprising a plurality of serially related individual coil sections carrying successively higher potential, an insulating bandage for each of said coil sections and for the interconnections therebetween, said bandages being disposed in accordance with the serial relationship of said coil sections so that each successive bandage, except the bandage for the last coil, includes all the coil sections and all interconnections between the coil sections which carry. successively higher potential, a Roentgen tube for receiving said high voltage, a heating transformer for said Roentgen tube, a conductive layer for each of said bandages which is coextensive each with its corresponding bandage and is connected with the lowest potential carried by any coil section included in said bandage, said bandages and the conductive layers thereof extending around said tube in accordance with the potential distribution thereof and also extending around the secondary winding of said heating transformer.

10. A device for producing very high voltages comprising a plurality of serially related individual coil sections carrying successively higher potential, an insulating bandage for each of said coil sections and for the interconnections therebetween, said bandages being disposed in accordance with the serial relationship of said coil sections so that each successive bandage, except the bandage for the last coil, includes all the coil sections and all interconnections between the coil sections which carry successively higher potential, a Roentgen tube for receiving said high voltage, a heating transformer for said Roentgen tube, a conductive layer for each of said bandages which is coextensive each with its corresponding bandage and is connected with the lowest potential carried by any coil section included in said bandage, said bandages and the conductive layers thereof extending around the secondary winding of said heating transformer and in staggered relation over said Roentgen tube in accordance with thepotential distribution thereof.

KURT BISCHOFF. 

